ARLINGTON, Texas — Hitting the 200-inning mark is a badge of honor for Dan Haren, who approaches the baseball season with a marathon runner’s mentality.

The A’s right-hander is one of the American League’s most durable pitchers, and the preparation he does to make sure he’s on the mound every fifth day is as important to him as his actual performance.

“In order to throw 200 innings, you have to be out there consistently six or seven innings,” Haren said. “That’s not an easy thing to do. Having done it two years in a row is something that means a lot to me.”

Haren and right-hander Joe Blanton, both 26, have the potential to anchor the A’s rotation for years to come should they stay in Oakland. Both are also among the American League leaders in innings pitched.

As the season’s final weeks unfold, now is the time when some teams start to scale down the innings for their top young pitchers for fear of arm injuries.

So the A’s face a delicate balancing act: They don’t want to overwork the promising young nucleus of their staff, particularly with the team out of the hunt in the AL West. At the same time, they don’t want to hold back pitchers such as Haren and Blanton, who show the ability and competitive desire to pitch late into games.

“I think we really trust the conditioning we do with the body and the arm,” A’s pitching coach Curt Young said. “Those two guys have never really had any setbacks. They’re guys who have prepared themselves to throw close to 240, 250 innings (a season), and you’re going to let them do that. Why slow them down when they’re anxious to pitch, you know?”

But it’s a relevant issue with the A’s entire starting staff. Chad Gaudin and Lenny DiNardo, the other two pitchers who have held down rotation spots most of the season, were slated to pitch out of the bullpen when spring training started and have logged heavier workloads than expected.

Gaudin, who was 8-3 with a 2.88 ERA before the All-Star break but is 2-7 with a 6.58 ERA since then, said he feels fine physically.

Haren, 14-6 with an AL-best 2.87 ERA, hasn’t been as dominant as he was in the first half, but he doesn’t attribute that to arm fatigue.

“Lately there’s been quite a few games where I’ve felt really good and I’ve still got hit around a little bit,” Haren said. “My fastball is still there. My arm strength is still there.”

Haren, who takes the mound in today’s series opener at Texas, ranks sixth in the American League with 191-1/3 innings. Last season he finished second in the AL at 223 innings, and will surely post his third straight 200-inning campaign.

Only Cleveland’s C.C. Sabathia has logged more innings in the AL this season than Blanton, who is at 205-1/3. Like Haren, Blanton (12-9, 3.81) has been a workhorse going on three seasons now. Blanton, Haren and Gaudin all said they’ve cut back their throwing between starts as the season’s progressed in hopes of keeping their arms fresh.

“I don’t have a really violent arm action or anything, I don’t throw super hard,” Blanton said. “I feel like I’m big and strong; that helps me be a guy who can go out every start and throw a lot of innings.”

The A’s always have leaned heavily on their top arms looking back through their recent history.

Barry Zito logged six straight seasons of 200-plus innings from 2001-06, Tim Hudson had four from 2000-03 and Mark Mulder notched three 200-plus innings in the same span. They were all in the early stages of their careers, like Haren and Blanton.

Of the “Three Aces,” only Mulder has fallen victim to serious arm or shoulder problems, and it’s unfair to assume Mulder’s can be attributed to overuse.

Go back a few years earlier, when an older core of pitchers dominated for the A’s. Dave Stewart never pitched fewer than 226 innings from 1987-91, topping out at a whopping 275ª innings in 1988. Mike Moore pitched at least 210 innings three times from 1989-92.

Haren said achieving that type of durability requires a pitcher to grit his teeth through pain sometimes.

“I would say more starts than not, I have something bugging me, whether it be my lower back or hip,” Haren said. “I know it’s the same way for Blanton. He’s had times this year when he’s had nothing, and he’s gone out there and still thrown up zeroes. If you’re a starting pitcher, you’ve got to go back out there.”